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Holly, MI, United States
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Tong X.C.,Laird
Springer Series in Advanced Microelectronics | Year: 2014

Optical fiber has been extensively used as a waveguide medium for telecommunication and computer networking because it is flexible and can be bundled as cables. It is especially advantageous for long-distance communications, because light propagates through the fiber with little attenuation compared to electrical cables. This allows long distances to be spanned with few repeaters. Additionally, the per-channel light signals propagating in the fiber have been modulated at rates as high as 100 or higher gigabits per second, although 10 or 40 Gbit/s is typical in deployed systems. Innovations in optical fiber technology are revolutionizing communication, and data processing systems. Newly developed fiber amplifiers, for instance, allow for direct transmission of high-speed signals over transcontinental distances without the need for electronic regeneration. Optical fiber technology including fiber materials, devices, and systems has become a rapidly evolving field. This chapter will give a brief review about basics, structures, materials, fabrication processes, and applications of optical fibers. © Springer International Publishing Switzerland 2014.


Tong X.C.,Laird
Springer Series in Advanced Microelectronics | Year: 2014

Optoelectronics is defined as the combined use of optical and electronic devices especially involving the interchange of visual and electronic signals. Integration of multiple optical functionalities onto planar substrates is being intensively pursued for a broad range of applications. Progress and success in the optoelectronic devices, such as fundamental transverse-mode laser diodes, low loss optical waveguides, and high quantum efficiency photodetectors, comprise a new and powerful class of monolithic integrated circuits for optical communications. Potential advantages of integrating optoelectronic devices on a single chip, as opposed to using hybrid optical and electronic systems, include increased reliability and reduced size of the circuitry and the reduction in unit cost due to mass production. Moreover, replacing the electrical connections between components with optical connectors increases the available bandwidth of the system and improves immunity to noise from electromagnetic interference. This chapter will give a brief overview about the optoelectronic devices and their integration. © Springer International Publishing Switzerland 2014.


Tong X.C.,Laird
Springer Series in Advanced Microelectronics | Year: 2014

The characterization of optical waveguides is a very important and essential step in any waveguide design and fabrication process. It is necessary to evaluate and confirm that the fabricated waveguide exhibits characteristics as designed. During materials selection and waveguide design, accurate measurements of key characteristics should be done with suitable methods. The major characteristics may include refractive index, layer thickness, optical coupling, optical loss, and nonlinear properties. Experimental evaluation and validation are necessary since these characteristics are rather difficult to determine theoretically. Such measurements provide important fundamental data to evaluate whether the waveguide is appropriate for integrated optical interconnection system, and use to specify the reason for the characteristics degradation. Therefore, the evaluation of the waveguide characteristics serves as a feedback to the design and the fabrication process, which is crucial for the modification and optimization of the waveguide performance. In this chapter, a series of optical waveguide characterization techniques will be elaborated. © Springer International Publishing Switzerland 2014.


Tong X.C.,Laird
Springer Series in Advanced Microelectronics | Year: 2014

Semiconductor optical waveguides are a very important part of modern integrated optoelectronic systems, especially for electrically active devices. Applications range from semiconductor lasers, optical filters, switches, modulators, isolators, and photodetectors. Semiconductor waveguides have many advantages especially for use in slow light applications. They offer a significant enhancement of interaction length that, to first order, scales with the possible delay. With a tight confinement of the optical mode, the required optical power can be drastically reduced while the mode overlap with the active material is strongly enhanced. The use of semiconductor material is of particular interest since it offers compactness and enables for monolithic integration into optoelectronic devices using well established processing techniques. Furthermore, semiconductors are attractive since the operating wavelength, to a large extend, can be designed while performing with bandwidths in the GHz regime that is well suited for communication signals. Based on III-V, II-VI, or IV-VI group elements, two semiconductors with different refractive indices are generally synthesized for fabrication of optical waveguides. They must have different band gaps but same lattice constant. An attractive feature of the binary compounds is that they can be combined or alloyed to form ternary or quaternary compounds, or mixed crystals, for varying the band gap continuously and monotonically together with the variation of band structure, electronic, and optical properties. The formation of ternary and quaternary compounds of varying band gaps also enables the formation of heterojunctions, which have become essential for the design of high performance electronic and optoelectronic devices. This chapter will give a brief review about fundamental theory, semiconductor materials, and fabrication technologies of various semiconductor waveguides. © Springer International Publishing Switzerland 2014.


Tong X.C.,Laird
Springer Series in Advanced Microelectronics | Year: 2014

Polymer optical waveguides would play a key role in broadband communications, such as optical networking, metropolitan access communications, and computing systems, due mainly to their easier processibility and integration over inorganic counterparts. The combined advantages also make them an ideal integration platform where foreign material systems, such as yttrium iron garnet and lithium niobate, as well as semiconductor devices such as lasers, detectors, amplifiers, and logic circuits can be inserted into an etched groove in a planar lightwave circuit to enable full amplifier modules or optical add/drop multiplexers on a single substrate. Moreover, the combination of flexibility and toughness in optical polymers makes it suitable for vertical integration to realize 3D and even all-polymer integrated optics. This chapter would provide a brief review about polymer-based optical waveguides, including suitable polymer waveguide systems, their processing and fabrication techniques, and the integrated optical waveguide components and circuits derived from these materials. © Springer International Publishing Switzerland.


Tong X.C.,Laird
Springer Series in Advanced Microelectronics | Year: 2014

Next-generation high-end data processing systems such as Internet switches or servers approach aggregate bandwidth in excess of 1 Tb/s. The task of providing hundreds of individual links as speeds in excess of 10 Gb/s over the link distances becomes increasingly difficult for conventional copper-based interconnect technology. Optical interconnects are foreseen as a potential solution to improve the performance of data transmission on chip, PCB, and system levels. They carry data signals as modulation of optical intensity, through an optical waveguide, thus replacing traditional electrical interconnects. Optical devices can overcome the bottleneck imposed by the limited bandwidth of electronic circuits in areas such as computing, data storage, or telecommunication networks. The basic element of any optical circuit is the optical waveguide, which permits to connect optically different devices. To build integrated optical circuits that substitute micro-electronic circuits, integrated optical waveguides with light confinement in a size of the order of the wavelength are mandatory. Optical waveguides can be classified according to their geometry (planar, strip, or fiber waveguides), mode structure (single-mode, multimode), refractive index distribution (step or gradient index) and material (glass, polymer, or semiconductor). They are designed as energy flow only along the waveguiding structure but not perpendicular to it, so radiation losses can be avoided. Usually, optical integrated waveguides rely on the principle of total internal reflection, using materials with low absorption loss. The waveguide cross section should be as small as possible to permit high-density integration, functionally linking devices or systems or implementation of complex functionalities, such as splitters/combiners, couplers, AWGs, and modulators. A wide range of materials can be used, with their corresponding advantages and drawbacks. Current commercial devices are mostly based on silicon/silica waveguides, III-V compounds, and lithium niobate waveguides. Silicon waveguides offers the possibility of mass-manufacturing and a high level of integration, which would result in cheaper chips. Novel materials such as photonic crystals can provide advantages to fulfill the requirements for high-density photonic integration. This chapter will review fundamentals and design guides of optical waveguides, including state-of-the-art and challenges, fundamental theory and design methodology, fabrication techniques, as well as materials selection for different level waveguide components and integration structures. © Springer International Publishing Switzerland 2014.


Tong X.C.,Laird
Springer Series in Advanced Microelectronics | Year: 2014

Hollow-core waveguides (HCWs) are comprised of a central hole surrounded by a highly reflective inner wall. The core can be filled with air, inert gas, liquid, or vacuum, allowing these waveguides to transmit a broad range of wavelengths with low attenuation. HCWs are of particular interest for the transmission of infrared (IR) to THz radiation, where it is otherwise difficult to find materials that have the optical, thermal, and mechanical properties required for use in solid-core optical fibers. Therefore, IR-transmitting hollow waveguides can be an attractive alternative to solid-core IR fibers. Hollow waveguides can be made from plastic, metal, or glass tubes that have highly reflective coatings deposited on the inside surface. These waveguides have losses as low as 0.1 dB/m at 10.6 mm and may be bent to radii less than 5 cm. For use in high-power laser delivery applications, the waveguides have shown to be capable of transmitting up to 3 kW of CO2 laser power. They are also finding uses in both temperature and chemical fiber sensor applications. This chapter will give a brief review about the progress in hollow waveguide technology with emphasis on the available hollow waveguides that have been developed. © Springer International Publishing Switzerland 2014.


Tong X.C.,Laird
Springer Series in Advanced Microelectronics | Year: 2014

While developed for the needs of microelectronics, the silicon-on-insulator (SOI) wafers are excellent substrates for optical waveguides. SOI is a kind of structures formed by a thin layer of crystalline silicon (Si) on an insulating layer, which typically is silicon dioxide (SiO2). SOI optical waveguides possess unique optical properties due to the high transparency of silicon in the infrared spectrum and the large refractive index difference between silicon (guiding layer or core, n = 3.45) and SiO2 (insulator layer or cladding, n = 1.46). This high difference in indices of refraction strongly confines the electromagnetic field into the silicon layer. The widely used SOI waveguides may take the form of a channel waveguide, ridge waveguide, photonic-crystal waveguide, or slot waveguide. The photonic-crystal waveguide is an exceptional option for making SOI waveguides. The refractive indices of different areas of the cladding can be flexibly engineered by varying the diameter of the holes and the lattice constants. These excellent optical properties, as well as compatibility with silicon complimentary-metal-oxide semiconductor (CMOS) integrated technology, enable low-cost and dense optoelectronic integrated circuits. In fact, SOI material has become a main platform for both photonics and VLSI CMOS electronics, with fully compatible processing procedures. This chapter will give a brief review about the principle design, materials selection, and fabrication process of the SOI waveguides. © Springer International Publishing Switzerland 2014.


Tong X.C.,Laird
Springer Series in Advanced Microelectronics | Year: 2014

Optical waveguide components have been made with various glasses for commercial photonic devices, such as phase-arrays, and Mach-Zehnder interferometer switches. The devices are based on planar optical waveguides, in which light is confined to substrate-surface channels and routed onto the chip. Silica, SiON, fluoroaluminates, chalcogenides and doped glasses are important glasses for making optical waveguide devices. Bulk silica (SiO2) and silica-on-silicon (SiO2/Si) are by far the most common materials used to manufacture planar light wave circuits (PLCs), due to their refractive-index match with silica-based optical fiber. Doped glass and silica waveguide-based PLC technology is a promising way to integrate optical devices and thus reduce the receiver size and cost. Glass/silica waveguide PLCs typically consist of a planar arrangement of glass waveguides with a higher index of refraction buried in glass all on a silicon or glass substrate. Glass/silica waveguide PLCs have successfully used in optical fiber communications because of their reliability, low insertion loss, ease of coupling to optical fibers, integration capability, and ability to produce optical filters with high accuracy. This chapter will provide an overview about glass-based waveguide devices, including materials selection, fabrication process and applications. © Springer International Publishing Switzerland 2014.


News Article | November 16, 2016
Site: www.prnewswire.com

SCHAUMBURG, Ill., Nov. 16, 2016 /PRNewswire/ -- The mobile industry's thinnest, smallest ceiling or wall-mounted wideband antenna that is more efficient and meets the design needs of office and apartment buildings, hotels, airports, and other large coverage areas, was announced today by...

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